1. Field of the Invention:
This invention is in the field of chemical reactor machines for reacting one or more porous solid reactants with one or more gaseous reactants, wherein compression of gaseous reactants into the pore spaces of the solid reactant is followed by expansion of the resultant product gases out of these pore spaces, and this cycle of compression and expansion is repeated.
2. Description of the Prior Art:
Examples of prior art reactors for reacting solid reactants with gaseous reactants are described in the following U.S. patents:
U.S. Pat. No. 4,372,256, J. C. Firey, Feb. 8, 1983 PA1 U.S. Pat. No. 4,412,511, J. D. Firey, Nov. 1, 1983 PA1 U.S. Pat. No. 4,455,837, J. C. Firey, June 26, 1984 PA1 U.S. Pat. No. 4,484,531, J. C. Firey, Nov. 27, 1984 PA1 U.S. Pat. No. 4,509,957, J. C. Firey, Apr. 9, 1985 PA1 U.S. Pat. No. 4,533,362, J. C. Firey, Aug. 6, 1985 PA1 U.S. Pat. No. 4,537,603, J. C. Firey, Aug. 27, 1985 PA1 U.S. Pat. No. 4,568,361, J. C. Firey, Feb. 4, 1986
In all of the above example reactors the gaseous reactants are compressed into the pore spaces of the solid reactants contained within a reaction chamber, and this is followed by expansion of the primary product reacted gases, formed by reaction of the reactant gases with the solid reactants, out of the pore spaces of the solid reactant. This cycle of compression followed by expansion is repeated, with fresh gaseous reactants being supplied for each compression and with product reacted gases being removed during each expansion. Such chemical reactors for reacting solids with gases and using this cyclic compression and expansion process are herein and in the claims referred to as cyclic solid with gas reaction plants.
The term solid reactant is used herein and in the claims to include wholly solid materials as well as solids whose surface is wetted with a liquid. A single solid reactant can be but a single chemical or a mixture of several different chemicals.
The term gas reactant is used herein and in the claims to include single gaseous chemicals as well as mixtures of several different gaseous chemicals.
The term reacted gas is used herein and in the claims to include single gases or mixtures of different gases.
The term changeable gas flow connection is used herein and in the claims to mean a gas flow connection which can be opened or closed while the plant is operating. The term fixed open gas flow connection is used herein and in the claims to mean a gas flow connection which remains open whenever the plant is operating.
In many cyclic solid with gas reaction plants at least two steps of chemical reaction occur: a primary reaction between gas reactant and solid reactant during compression; a secondary reaction between the primary product reacted gas from the primary reaction and additional gas reactant during expansion. The primary reaction takes place principally within the pore spaces of the solid reactant whereas the secondary reaction takes place principally outside the pore spaces of the solid reactant. A volume or space wherein chemical reaction occurs is herein and in the claims referred to as a reaction chamber. For example, the pore spaces within the solid reactant are a primary reaction chamber, whereas any gas space outside this primary reaction chamber may be a secondary reaction chamber if secondary reactions occur there. These primary and secondary reaction chambers may be separately enclosed by the containing walls of separate pressure vessels or may be jointly enclosed within the containing walls of a single pressure vessel.
Where secondary reactions take place between primary product reacted gas and additional reactant gas during expansion, the proper mixing of these gases for complete and rapid secondary reaction cannot always be assured when only primary and secondary reaction chambers are used. For example, in the char and oil burning engines described in U.S. Pat. No. 4,412,511, when high volatile matter char fuels are used, it is important that this volatile matter by promptly mixed with air reactant as soon as it emerges from the char fuel pores during expansion in order to avoid soot formation. This mixing of air with volatile matter is described in U.S. Pat. No. 4,412,511, in column 13 lines 49 through 54, and this material is incorporated herein by reference thereto. But with only the primary reaction chamber available for this reaction and essentially filled with char fuel, most of the air reactant supplied to the primary reaction chamber during compression will be used up in the primary reaction. Hence during expansion, when the volatile matter is emerging from the char fuel pores at the refuel end of the primary reaction chamber, the air quantity available may be inadequate for proper and complete mixing and reaction with this volatile matter and soot formation may result. Such soot formation may reduce combustion efficiency and produce engine exhaust smoke.
Another example problem is seen in the secondary reaction of primary reacted gases with secondary air in a cyclic velox boiler as described in U.S. Pat. No. 4,455,837. The manner of occurrence of this secondary reaction when only primary and secondary reaction chambers are used is described in U.S. Pat. No. 4,455,837, in column 41 line 62 through column 44 line 21, and this material is incorporated herein by reference thereto. As discussed therein proper mixing and reaction of the emerging primary reacted gases with the secondary air reactant gases during expansion cannot always be assured. Rather complex gas flow control means may sometimes be required, as described, to improve this mixing and reaction.